U.S. patent number 6,572,372 [Application Number 09/616,222] was granted by the patent office on 2003-06-03 for embedded features and methods of a dental appliance.
This patent grant is currently assigned to Align Technology, Inc.. Invention is credited to Jae Hyun Ahn, Muhammad Chishti, Eric Kuo, Ross J. Miller, Loc X. Phan, H. Robert Van Den Berg.
United States Patent |
6,572,372 |
Phan , et al. |
June 3, 2003 |
Embedded features and methods of a dental appliance
Abstract
Traditional orthodontic treatment often involves the use of
basic repositioning devices, such as braces, and the use of
supplementary devices, components or accessories to achieve desired
end results. Such components may be mounted on fixed, non-removable
devices or they may be part of a removable appliance typically worn
prior to the application of the fixed devices. As with traditional
treatment, it may be desired to utilize similar components when
repositioning teeth with removable elastic repositioning
appliances. Due to the nature of elastic appliances, such
components may take a variety of forms ranging from readily
available traditional accessories to specially created devices.
Thus, traditional components may be mounted on or embedded in an
elastic appliance, or the appliance may be formed to provide
similar components. Likewise, the appliance may be modified to
provide additional features for specific orthodontic
treatments.
Inventors: |
Phan; Loc X. (Milpitas, CA),
Chishti; Muhammad (Sunnyvale, CA), Miller; Ross J.
(Sunnyvale, CA), Van Den Berg; H. Robert (San Ramon, CA),
Kuo; Eric (San Francisco, CA), Ahn; Jae Hyun (San
Francisco, CA) |
Assignee: |
Align Technology, Inc. (Santa
Clara, CA)
|
Family
ID: |
27394049 |
Appl.
No.: |
09/616,222 |
Filed: |
July 14, 2000 |
Current U.S.
Class: |
433/6;
433/18 |
Current CPC
Class: |
A61C
7/00 (20130101); A61C 7/08 (20130101); A61C
7/36 (20130101) |
Current International
Class: |
A61C
7/00 (20060101); A61C 7/36 (20060101); A61C
7/08 (20060101); A61C 007/00 () |
Field of
Search: |
;433/6,18,20,24,215
;128/861 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2369828 |
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Jun 1978 |
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FR |
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WO 94/10935 |
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May 1994 |
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WO |
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WO 98/32394 |
|
Jul 1998 |
|
WO |
|
WO 98/58596 |
|
Dec 1998 |
|
WO |
|
Other References
Andrews, "The Six Keys to Optimal Occlusion" Straight Wire, Chapter
3 pp13-24. .
Biostar Opeation & Training Manual. Great Lakes Orthodontics,
Ltd. 199 Fire Tower Drive, Tonawanda, New York. 14150-5890. 20
pages total. .
Chiappone, "Constructing the gnathologic setup and positioner" J.
Clin. Orthod. (1980) 14:121-133. .
Cottingham, "Gnathologic clear plastic positioner" Am. J. Orthod.
(1969) 55:23-31. .
Cureton, "Correcting malaligned mandibular incisors with removable
retainers" J. Clin. Orthod. (1996) 30:390-395. .
Dent-X posted at http://www.dent-x.com/DentSim.htm Sep. 24, 1998, 6
pages total. .
Elsasser, "Some observations on the history and uses of the Kesling
positioner" Am. J. Orthod. (1950) 36:368-374. .
Kamada et al., "Case reports on tooth positioners using LTV vinyl
silicone rubber" J. Nihon University School of Dentistry (1984)
26(1):11-29. .
Kamada et al., "Construction of tooth positioners with LTV vinyl
silicone rubber and some case reports" J. Nihon University School
of Dentistry (1982) 24(1):1-27. .
Kesling, "Coordinating the predetermined pattern and tooth
positioner with conventional treatment" Am. J. Orthod. Oral. Surg.
(1946) 32:285-293. .
Kesling, "The philosophy of the tooth positioning appliance" Am. J.
Orthod. Oral. Surg. (1945) 31(6):297-304. .
Kleeman et al., "The speed positioner" J. Clin. Orthod. (1996)
30:673-680. .
Kunii et al., "Articulation Simulation for an Intelligent Dental
Care System" Displays (1994) 15:181-188. .
Kuroda et al., "Three-dimensional dental cast analyzing system
using laser scanning" Am. J. Orthod. Dentofac. Orthop. (1996)
110:365-369. .
Nahoum et al., "The vacuum formed dental contour appliance" The New
York State Dental Journal (1964) 30(9):385-390. .
Nippon Dental Review "New orthodontic device-dynamic positioner
(D.P.)-I. Approach to the proposal of D.P. and transparent silicone
rubber" (1980) 452:61-74. .
Nippon Dental Review, "New orthodontic device-dynamic positioner
(D.P.)-II. Practical application and construction of D.P." (1980)
454:107-130. .
Nippon Dental Review "New orthodontic device-dynamic positioner
(D.P.)-III. Case reports of reversed occlusion" 1980) 457:146-164.
.
Nippon Dental Review "New orthodontic device-dynamic positioner
(D.P.)-Case reports of reversed occlusion" (1980) 458:112-129.
.
Nishiyama et al., "A new construction of tooth repositioner by LTV
vinyl silicone rubber" J. Nihon University School of Dentistry
(1977) 19(2):93-102. .
Cardinal Industrial Finishes, Powder Coatings information posted at
http://www.cardinalpaint.com on Aug. 25, 2000, 2 pages total. .
Proffit et al, "Contemporary Orthodontics" Second Edition, Chapter
15, pp 470-533. .
Raintree Essix.TM. & ARS Materials, Inc., Raintree Essix.TM.
Technical Magazine Table of Contents and Essix.TM. Applications,
http://www.essix.com/magazine/default.html (Aug. 13, 1997) 7 pages
total. .
Richmond et al., "The development of the PAR Index (Peer Assessment
Rating): reliability and validity" European Journal of Orthodontics
(1992) 14:125-139. .
Schroeder et al., Eds. The Visual Toolkit, Prentice Hall PTR, New
Jersey (1998) Chapters 6, 8, and 9 (pp. 153-210, 309-354, and
355-428, respectively). .
Shilliday, "Minimizing finishing problems with the mini-positioner"
Am. J. Orthod. (1971) 59:596-599. .
Warunek et al., "Clinical use of silicone elastomer appliances" JCO
(1989) XXIII(10):694-700. .
Warunek et al., "Physical and mechanical properties of elastomers
in orthodontic positioners" Am. J. Orthod. Dentofac. Orthop. (1989)
95:388-400. .
Wells, "Application of the positioner appliance in orthodontic
treatment" Am. J. Orthodont. (1970) 58:351-366..
|
Primary Examiner: Shaver; Kevin
Assistant Examiner: Bumgarner; Melba
Attorney, Agent or Firm: Townsend and Townsend and Crew LLP
Thompson; Lynn M.
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
This Application claims the benefits of prior provisional
application Nos. 60/199,649 and 60/199,650, both filed on Apr. 25,
2000, the full disclosures of which are incorporated herein by
reference. The disclosure of this application is related to
copending application Ser. No. 09/616,830, filed on the same day,
the full disclosure of which is incorporated herein by reference.
Claims
What is claimed is:
1. A removable dental positioning appliance comprising: a polymeric
shell having cavities shaped to receive and reposition teeth from a
first orientation to a successive orientation and at least one
space filler shaped to align with a gap between adjacent teeth,
wherein the at least one space filler is a corrugated structure
between adjacent teeth.
Description
BACKGROUND OF THE INVENTION
The present invention is related generally to the field of
orthodontics. Particularly, this invention relates to the use of
removable orthodontic appliances for producing tooth movements.
More particularly, this invention relates to improved devices,
systems and methods for producing such tooth movements with elastic
repositioning appliances.
Orthodontic treatments involve repositioning misaligned teeth and
bite configurations for improved cosmetic appearance and dental
function. Repositioning teeth is accomplished by applying
controlled forces to the teeth over an extended period of time.
This is conventionally accomplished by wearing what are commonly
referred to as "braces." Braces are typically comprised of brackets
or bands which are bonded to the teeth and linked with the use of
archwires, ligatures and O-rings. After the archwire is in place,
periodic appointments with the orthodontist are required, during
which the patient's braces will be adjusted. This involves
installing different archwires having different force-inducing
properties or by replacing or tightening existing ligatures.
Between meetings, the patient may be required to wear supplementary
appliances, such as elastic bands or headgear, to supply additional
or extraoral forces.
Although conventional braces are effective, they are often a
tedious and time consuming process requiring many visits to the
orthodontists office. Moreover, from a patient's perspective, they
are unsightly and uncomfortable. The archwire and ligatures which
connect the brackets in a continuous network make brushing,
flossing between the teeth and other dental hygiene procedures
difficult, possibly contributing to the development of gingivitis,
caries, and other dental disease. Consequently, alternative
orthodontic treatments are needed. In particular, it would be
desirable to use appliances which can be removed by the patient
during daily dental hygiene routines, while participating in
athletic activities, or for cosmetic purposes.
A particularly promising approach relies on the use of elastic
positioning appliances for realigning teeth. Such appliances
comprise a thin shell of elastic material that generally conforms
to a patient's teeth but is slightly out of alignment with the
initial tooth configuration. Placement of the elastic positioner
over the teeth applies controlled forces in specific locations to
gradually move the teeth into the new configuration. Repetition of
this process with successive appliances comprising new
configurations eventually move the teeth through a series of
intermediate configurations to a final desired configuration. A
full description of an exemplary elastic polymeric positioning
appliance is described in U.S. Pat. No. 5,975,893, and in published
PCT application WO 98/58596 which designates the United States and
which is assigned to the assignee of the present invention. Both
documents are incorporated by reference for all purposes.
In addition to their ease of use, polymeric positioning appliances
are generally transparent, providing an improved cosmetic
appearance, and impart substantial force on the teeth, due to
stiffness of the appliance. The stiffiess of an elastic positioning
appliance is a result of the modulus of the thermoformable polymer
materials from which it is made. The higher the modulus of the
materials, the higher the stiffness of the appliance. By designing
the appliance to cover the teeth, a much larger and/or more varied
contact surface area may be afforded compared to traditional spring
retainers and wire-based appliances. Consequently, more dramatic
tooth movements may be achieved.
In some cases, however, orthodontic treatment may involve more
complex tooth movements or treatment plans requiring additional
devices or accessories. For example, it may be desirable to apply
forces to surfaces of the teeth that may not be easily achieved by
the appliance alone, either due to the location or characteristics
of the surface itself or of the surrounding teeth. Similarly, it
may be desirable to apply extraoral forces to some tooth surfaces
to achieve certain tooth movements or to control growth and
development of the bite and jaws. Likewise, it may be desirable to
achieve such control indirectly through soft tissue stretch and
muscular activity. Alternatively, it may be preferable to allow the
passive eruption and movement of certain teeth, free of applied
forces. The devices and accessories commonly utilized for these
situations are typically separate removable appliances worn prior
to the application of conventional braces, or accessories used in
conjunction with conventional braces. Thus, such devices and
accessories may not be compatible with the use of elastic polymeric
positioning appliances for orthodontic treatment.
Consequently, improved methods and apparatus for achieving these
treatment objectives are desired for complete orthodontic treatment
in such patients. Such devices, systems and methods would maintain
the advantages of and be compatible with a removable appliance
while providing supplementary features to assist in the improvement
of jaw structuring, alignment and tooth repositioning, to name a
few. At least some of these objectives will be met by the designs
and methods of the present invention described hereinafter.
SUMMARY OF THE INVENTION
The present invention provides improved devices, systems and
methods for repositioning teeth from a first orientation to a
successive orientation in a series of movements to a final tooth
and bite configuration. Such repositioning is based on a system
comprising at least one and usually a plurality of three or more
elastic repositioning appliances configured to receive the teeth in
a cavity and incrementally reposition individual teeth, usually in
a series of successive steps. In cases involving more complex
movements or treatment plans, it may be desired to utilize
additional devices, components or accessories. The present
invention provides for the utilization of such devices, components
or accessories typically used in conventional orthodontic
treatment. In some instances the present invention provides
improved elastic repositioning appliances that take the place of
such additional accessories. Further, the present invention may
provide improved elastic repositioning appliances that provide
simultaneous repositioning of tooth and bite configurations that
may be unachievable with conventional devices.
In a first aspect of the present invention, a removable elastic
positioning appliance, typically used in a series of successive
elastic appliances for orthodontic treatment, may be comprised of a
polymeric shell having at least one orthodontic component or
accessory. These components or accessories may be independent
entities that are embedded in the polymeric shell during production
of the appliance. Or, they may be mounted on the polymeric shell
with a suitable adhesive in a post-production assembly protocol. In
either case, the components may be traditional accessories that are
typically used with conventional orthodontic devices, such as
braces, or they may be any other readily available components used
for dental treatment. Alternatively, the components may be
specially created accessories designed for specific purposes when
used with removable elastic positioning appliances. Such specially
created accessories may be independent entities present on or in
the polymeric shell as described above, or they may be formed by
the polymeric shell itself. In these cases, the component may be a
formed protrusion or shape in the wall of the polymeric shell,
providing a variety of advantages, including but not limited to
increased stability, safety from breakage, ease of manufacturing,
cost savings, shortened treatment time and improved cosmetic
appearance and patient compliance.
In a first embodiment, the orthodontic components or accessories
may be conventional accessories typically used with fixed,
non-removable orthodontic devices. For example, headgear tubes are
conventional accessories typically mounted on traditional braces
for inserting a headgear device and applying extraoral force to the
teeth and jaws. Tubes for receiving headgear may be mounted on or
embedded in the polymeric shell of an elastic positioning appliance
for a similar effect. Similarly, orthodontic hooks may be mounted
on traditional braces to support elastic bands which may also apply
distinct forces to the teeth and jaws. As with headgear tubes, such
hooks may also be mounted on or embedded in the polymeric shell of
a positioning appliance for a similar effect. Likewise, a number of
other conventional accessories, such as brackets, springs, bumper
tubes, palatal bars, frameworks, pin-and-tube apparatuses and the
like, may be used in conjunction with polymeric positioning
appliances. In some cases, such as with brackets, the accessory may
be used to join a removable elastic appliance with a portion of
teeth supporting fixed conventional devices, such as braces.
In a second embodiment, the orthodontic components or accessories
may be those which are primarily exclusive to removable appliances.
These components are not generally suited for use with fixed
appliances and devices due to their bulk and size. In addition,
they are often used prior to the use of fixed devices to create a
favorable environment for later tooth repositioning. For example,
when a patient's teeth are still erupting, a number of devices may
be used to foster improved eruption and development of the tooth
arrangement and bite configuration. These may include buccal
shields, buccinator bows or wire shields, bite plates, palatal
expanders and bars, lingual flanges and pads, lip pads or bumpers,
and the like. Since these components are currently used with
removable appliances, they are ideally suited for use with
removable elastic positioning appliances. Thus, the components may
be mounted on or embedded in the polymeric shell of an elastic
appliance. Similarly supporting structures for such components may
also be mounted or embedded in the polymeric shell for the
removable application of a component. For example, a bumper tube
may be embedded in the polymeric shell for later insertion and
removal of a bumper. Alternatively, the components may be formed by
the appliance itself, such components comprising a formed
protrusion or shape in the wall of the polymeric shell. In these
cases, the elastic repositioning appliance may take the place of
any additional accessories.
An added advantage of the use of elastic repositioning appliances
having these components or accessories is the ability to provide
the conventional benefit of the accessory while simultaneously
repositioning the teeth, a combination previously limited. In
conventional treatment, the use of fixed devices to reposition the
teeth negated the ability of simultaneously using accessories
provided by some removable appliances since removable appliances
may not be readily applied with fixed devices in place. For
example, situations in which it is desired to control eruption of
specific teeth concomitant with repositioning of the same or other
teeth would cause great difficulty if not an impossible dilemma
with traditional devices. The present invention may provide such
simultaneous maneuvers which are unachievable with conventional
treatment.
In a second aspect of the present invention, a removable dental
positioning appliance, typically used in a series of successive
elastic appliances for orthodontic treatment, may be comprised of
at least one protrusion shaped to be used for an orthodontic
function. As described above, such a protrusion may resemble, in
form or function, a traditional component or accessory used in
conventional orthodontic treatment with fixed, non-removable
devices or with removable appliances. For example, an appliance may
have a protrusion or shape in the wall of the polymeric shell in
the form of a hook for mounting flexible bands, ligatures or
adjunct devices. Such a hook may resemble traditional hooks found
in dental care, or it may be specially designed for use with
elastic repositioning appliances. Likewise, such a protrusion may
form a spring which transmits force to one or more teeth to
reposition teeth from a first arrangement to a successive
arrangement. A spring of this type may be of a traditional design
or it may be specially designed for use with elastic repositioning
appliances. Further, it may be specially designed to engage an
attachment body mounted on a tooth, a device primarily utilized in
conjunction with removable elastic appliances. A full description
of exemplary attachment bodies and devices is described in
published PCT application WO 99/28228, which corresponds to
co-pending application Ser. No. 09/454278, assigned to the assignee
of the present invention. Both documents are incorporated by
reference for all purposes. Thus, in these and similar cases, such
as a palatal bar, the protrusion may take the place of a
traditional accessory or component, or it may be utilized in a
specialized manner.
In one embodiment, the protrusion may contact one or more dental
surfaces to assist in holding the elastic appliance in position.
For example, one or more protrusions may be sized and located to
contact interdental areas of the patient's teeth, often near the
gingival margin, when the appliance is properly inserted and
positioned. Such protrusions may be formed in the wall of the
polymeric shell, or they may be adhered to or embedded into the
polymeric shell to protrude from the wall. Such placement of the
protrusions may provide additional friction and "grab" in dental
regions conducive to this effect. Similarly, a protrusion may be
sized and located to contact a tooth along a portion of the
gingival margin, with or without contact in the interdental areas.
Or, the protrusion may be a continuous protrusion contacting more
than one tooth along the gingival margin and the interdental areas.
In each of these cases, the contact of the protrusion may assist in
holding the appliance in proper position.
In another embodiment, the one or more protrusions may form a bite
plate. A bite plate is a device which prevents the teeth from
closing completely. By opening the bite in this manner, unopposed
teeth may be allowed to passively erupt in a controlled manner to
beneficially alter vertical dental relationships. In addition, such
an open state or disclusion may relieve teeth which are in
crossbite allowing orthodontic forces to correct the crossbite.
To provide anterior disclusion, an elastic positioning appliance
may have an increase in thickness of material in the posterior
occlusal regions. This increase in thickness may be applied to the
appliance or formed by the appliance to create a protrusion over
the designated occluding surfaces. Similarly, posterior disclusions
may be provided by forming a protrusion which extends at least a
portion of an upper palatal region with added thickness.
Alternatively, posterior disclusions may be provided by forming a
protrusion in an upper lingual or lower facial anterior region.
Such protrusions may prevent the front teeth from closing
completely, thus discluding the posterior teeth. As previously
described, such protrusions may be formed in the appliance or
applied to the surface of the appliance.
Such embodiments of the present invention may be utilized in the
treatment of patients with a condition commonly termed a "deep
bite". In these cases, the lower teeth contact the upper teeth
and/or the palate in the natural bite. This occurs when the
posterior teeth are not fully erupted in the correct position
allowing the anterior teeth to become overdosed or overlap more
than is desirable. Such a bite is injurious to the palate, tends to
crowd the lower teeth, and affects flaring of the upper teeth
leading to upper spaces. This may be alleviated with the use of a
bite plate which provides posterior disclusion. Such disclusion
allows the posterior teeth to naturally erupt without contacting
the opposing teeth which may impede their eruption into the correct
position. The present invention may provide the function of a bite
plate while additionally providing repositioning forces and other
orthodontic treatment to the patient. These functions may be
simultaneous, an attribute not previously afforded by conventional
orthodontic treatment.
In a third aspect of the present invention, a removable dental
positioning appliance, typically used in a series of successive
elastic appliances for orthodontic treatment, may be comprised of
at least one space filler shaped to align with a gap between
adjacent teeth. If a tooth is extracted from a patient's dentition,
a space or gap will be left behind between adjacent teeth. A
similar gap may also be present due to general misalignment of the
teeth. An elastic positioning appliance may be made to be
positioned over a gap and its surrounding teeth. In such a case, a
space filler may be shaped to align with the gap. In a preferred
embodiment, the space filler may be a cavity in the polymer shell
having the shape of at least a portion of a tooth, dental feature,
sphere, oval or three-dimensional curved and/or flat sided object.
In the case of a tooth shape, the space filler may act as a
"pontic," a fake tooth placed where a tooth is missing to give the
appearance of the presence of a tooth. This same effect may also be
given by other shapes. Likewise, as a gap is gradually eliminated
due to repositioning of the teeth, a variety of shapes may be
suitable throughout the repositioning process.
To further conceal the presence of a space or gap between teeth
during orthodontic treatment, a space filler may be opacified. By
making the space filler at least partially opaque, it may give a
more convincing appearance of the presence of a tooth or dental
feature. Such opacity may be an effect of surface treatment of the
space filler. For example, the inside and/or outside surfaces of
the space filler may be painted with a tooth-colored material.
Alternatively, the surfaces may be microetched to give a more
frosted appearance to the polymeric shell material. In either case,
the space or gap may be less visible.
In addition to improving cosmetic appearance, a space filler may
also provide structural support for the elastic appliance. When a
space filler is a cavity, as described above, the presence of the
cavity improves the structural integrity of the appliance by
providing a uniform geometry. Alternatively, a space filler may be
any number of structures providing similar support. For example, a
space filler may be a structure that is at least partially solid.
This may be achieved by the formation of a solid section of
material spanning the gap, similar to a bridge or slab between
adjacent teeth. Such a solid section may be formed by the fusing of
the walls of the polymeric shell together. Alternatively, the shell
may be filled with a solid material. In this case, the shell may be
designed with undercuts or prongs to retain the solid material. In
addition, a solid section may be corrugated to additionally improve
the integrity of the appliance.
In a fourth aspect of the present invention, a removable dental
positioning appliance, typically used in a series of successive
elastic appliances for orthodontic treatment, may be comprised of a
polymeric shell having cavities shaped to receive and reposition
teeth, wherein one or more cavities has a window to expose at least
a portion of a received tooth. Such windows may be portions of the
wall of the polymer shell which are removed. When the shell is
positioned over the patient's teeth, portions of the teeth beneath
the windows may be exposed. Exposing such tooth surfaces may allow
brackets, buttons or other orthodontic components to be utilized in
conjunction with the elastic appliance or to be exposed for other
purposes.
In a preferred embodiment, a polymeric shell may have a plurality
of windows over portions of the occlusal surfaces of the teeth. In
this case, segments of the shell may still be present along the
facial and lingual surfaces of the teeth and across the interdental
regions or spaces between the teeth. Exposure of the occlusal
surfaces in appropriate size and location may allow interdigitation
of the upper and lower teeth. This may also be achieved with the
presence of one or a few larger windows over portions of the
occlusal surfaces of the teeth. In these cases, segments of the
shell may not be present across the interdental regions or spaces
between the teeth. In either case, interdigitation of at least
portions of the upper and lower teeth may benefit tooth and jaw
orientations, leading to improved treatment, appearance, comfort
and consequently patient compliance. Likewise, similarly placed
windows may provide the benefits offered by a lower elastic
modulus, such that the lowest stiffness may be provided by the
absence of the material. Such benefits and a full description is
provided in co-pending application Ser. No. 09/616,830, assigned to
the assignee of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective illustration a variety of orthodontic
components or accessories typically used with fixed orthodontic
devices mounted on or embedded in the polymeric shell of a
removable elastic repositioning appliance.
FIG. 2 is a perspective illustration of a typical transpalatal arch
bar mounted on or embedded in the polymeric shell of an
appliance.
FIG. 3 is a perspective illustration an appliance having a lip
pad.
FIG. 4 is a perspective illustration of an appliance having a
buccal shield.
FIG. 5 is a perspective illustration of an appliance having
buccinator bow.
FIG. 6 is a perspective illustration of an appliance having lingual
pad.
FIG. 7 is a perspective illustration of appliances joined by
frameworks used in Herbst Appliances.
FIG. 8 is a perspective illustration of appliances joined by
frameworks used in Jasper Jumpers.
FIG. 9 illustrates of an appliance having a protrusion formed in
the polymeric shell in the shape of a hook.
FIGS. 10A and 10B illustrate steps of producing a protrusion
depicted in FIG. 9.
FIG. 11 illustrates an appliance having a protrusion formed in the
polymeric shell in the shape of a spring.
FIG. 12 is a perspective illustration of an appliance having a
protrusion in the polymeric shell to form a transpalatal bar.
FIG. 13 is a perspective illustration of an appliance having a
corrugated protrusion in the polymeric shell to form a transpalatal
bar.
FIG. 14A is a side view of a patient's teeth showing the placement
of protruding divots contacting interdental areas, and FIG. 14B is
a perspective illustration of a portion of an appliance having such
divots.
FIG. 15A is a perspective illustration of a portion of an appliance
having a continuous protrusion along the gingival line, and FIG.
15B is a cross-sectional view of a tooth having such an appliance
in place.
FIG. 16 is a side view of a posterior portion of an appliance
illustrating an increase in thickness of material to form a bite
plate.
FIG. 17 is a perspective illustration of an appliance having a
protrusion of an upper palatal region to form a bite plate.
FIGS. 18A and 18B are cross-sectional views of appliances having
protrusions in an upper lingual and lower facial anterior regions,
respectively, to form bite plates.
FIG. 19 illustrates a patient having a gap between adjacent
teeth.
FIG. 20 is a perspective illustration of an appliance having a
space filler cavity in the shape of a tooth placed over the
patient's dentition illustrated in FIG. 19.
FIG. 21 is a perspective illustration of an appliance having a
space filling structure formed between two cavities in the
polymeric shell.
FIG. 22 is a perspective illustration of an appliance having a
space filling corrugated structure formed between two cavities in
the polymeric shell.
FIG. 23A illustrates an unwanted disclusion due to thickness of the
appliance along the occlusional surfaces. FIG. 23B illustrates the
elimination of the disclusion of FIG. 23A by eliminating material
along the occlusional surfaces. FIG. 23C illustrates a preferred
embodiment of an appliance with portions of the occlusional
surfaces eliminated.
FIG. 24A illustrates a release tab embedded in the polymeric shell
of an appliance. FIG. 24B illustrates a preferred embodiment of an
appliance with release tabs encircling areas of occlusional
surfaces of the appliance.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
Traditional orthodontic treatment often involves the use of basic
repositioning devices, such as braces, and the use of supplementary
devices, components or accessories to achieve desired end results.
As previously described, such supplementary components may be
mounted on fixed, non-removable devices or they may be part of a
removable appliance typically worn prior to the application of the
fixed devices. As with traditional treatment, it may be desired to
utilize similar supplementary components when repositioning teeth
with removable elastic repositioning appliances. Due to the nature
of elastic appliances, such components may take a variety of forms
ranging from readily available traditional accessories to specially
created devices, as will be described below.
Referring to FIG. 1, a variety of orthodontic components or
accessories typically used with fixed orthodontic devices, such as
braces, are shown in conjunction with a removable elastic
positioning appliance 10. The majority of these accessories may be
readily available since they are typically used with conventional
treatment. They are also typically mounted on fixed devices, so
they are available as separate individual components. As previously
described, these components may be embedded in the polymeric shell
12 of an elastic repositioning appliance 10 during production or
they may be mounted on the shell 12 in a post-production assembly.
One such type of component is a tube 14 which is used in pairs to
mount a headgear appliance. Headgear appliances are typically
mounted on opposite posterior molars of the upper jaw for a number
of purposes, including keeping the upper jaw from growing, pulling
the upper teeth backward, and pulling the upper jaw and teeth
upward and backward so that they align with the lower jaw and
teeth. Therefore, tubes 14 for receiving headgear may be mounted on
the buccal surfaces of the polymeric shell 12 covering the
posterior molars. The distal ends of the headgear which enter the
oral cavity may then be inserted into the tubes 14 to apply extra
oral forces to the teeth and jaw. Other components may include
hooks 16, primarily used for mounting elastic bands, brackets 18,
used for mounting additional components and accessories or possibly
for interconnection with fixed brackets or devices, and buttons 20,
primarily used as an attachment point for various purposes. It may
be appreciated that such components have been shown on the same
appliance 10 for illustrative purposes, however typical use may
involve one or a few of such components with varying
arrangements.
Referring to FIG. 2, an additional component which may be mounted
on or embedded in a polymeric shell 12 is a transpalatal arch bar
26. Such palatal bars typically span the palate and are fixed at
both ends to permanent devices mounted on opposing molars. This is
often used to stabilize and maintain positioning after active arch
expansion. In the case of an elastic repositioning appliance 10,
the conventional arch bar 26 may be positioned in a similar
location, attached at both ends to the polymeric shell covering the
lingual surfaces of opposing upper molars. In addition, a low
hanging transpalatal bar for control of vertical dimension may be
used. Also shown in FIG. 2, one or more wires 22 may be mounted on
or embedded in the polymeric shell 12. Such wires 22 may span the
majority of the arch, as in the case of a conventional archwire, as
shown. Or, such wires 22 may span only portions of the arch, may be
present on or within the facial and/or lingual surfaces of the
shell, may be multiple in number at a given location, and may be
curved, straight or a combination of these, to name a few. The
presence of such a wire 22 may be used most commonly for structural
reinforcement but may also be used to aid in the application of
orthodontic repositioning forces. Again, it may be appreciated that
such components have been shown on the same appliance 10 for
illustrative purposes, however typical use may involve one or a few
of such components with varying arrangements.
FIGS. 3-8 illustrate the use of a variety of orthodontic components
or accessories which are typically used with removable functional
appliances. These components are not generally suited for use with
fixed appliances and devices due to their bulk and size. However,
they may be readily used with removable elastic repositioning
appliances. In most functional appliances, flanges are used to
provide the stimulus to posture the mandible to a new position.
Growth modification is most effective if the patient uses his or
her own musculature to posture the mandible forward, as opposed to
the mandible being held forward by external pressure while the
patient relaxes. Thus, the key to mandibular repositioning is the
contact of the pad or flange with soft tissue. Such pads or flanges
may be mounted or embedded in elastic repositioning appliances.
Referring to FIG. 3, a lip pad 30 may be positioned on the
polymeric shell 12 so that it is low in the vestibule, holding the
lips away from the teeth and forcing the lips to stretch to form an
oral seal. This forces the lip musculature to stretch during
function, presumably improving the tonicity of the lips and perhaps
promoting some soft tissue remodeling that would contribute to
stability of changes in incisor position.
Referring to FIGS. 4 and 5, plastic buccal shields 34 and wire
buccinator bows 36 may be mounted on or embedded in the polymer
shell 12 to hold the soft tissues away from the teeth. A buccal
shield 34 or bow 36 may be positioned on the buccal surface of the
polymeric shell 12 to lie between the teeth and the cheek. The
buccal shield 34 is most useful to hold the cheek away from the
dentition to facilitate posterior dental expansion by disrupting
the tongue-cheek equilibrium. This in turn leads to facial movement
of the teeth and arch expansion. A combination of lip pads 30 and
buccal shields 34 will result in an increase in arch circumference
as well. It may be appreciated that similar shields may be mounted
on the lingual surface of the polymeric shell to remove the resting
tongue from between the teeth. This has the effect of enhancing
tooth eruption in designated areas. In addition, a lingual pad or
flange 38 may be positioned on the lingual surfaces of the
polymeric shell 12 covering the lower anterior teeth, as shown in
FIG. 6. The lingual pad 38 determines the anteroposterior and
vertical mandibular posture for most functional appliances. Such
pads 38 may not only position the mandible forward but also exert a
protrusive effect on the mandibular incisors when the mandible
attempts to return to its original position.
Referring to FIGS. 7 and 8, a number of components and accessories
may be removably or fixedly attached to both an upper and lower
elastic positioning appliance. Components commonly used in this
arrangement are frameworks used in Herbst Appliances and Jasper
Jumpers. Herbst Appliances are devices in which the maxillary and
mandibular arches are splinted with frameworks that are connected
with a pin-and-tube device that holds the mandible forward. When
used with elastic repositioning appliances, FIG. 7, the
pin-and-tube apparatus 40 may be mounted on the buccal surfaces of
the upper polymeric shell 42 and lower polymeric shell 44 as shown.
The Jasper Jumper functions in a similar manner as the maxillary
and mandibular arches are splinted with frameworks that are
connected with a spring covered by a plastic sheath. When used with
elastic repositioning appliances, FIG. 8, the sheath covered spring
48 may be mounted in a similar manner as shown.
As an alternative to mounting or embedding conventional orthodontic
components on an elastic repositioning device, protrusions or other
shapes may be formed in the polymeric shell of the device to be
used for orthodontic functions. For example, referring to FIG. 9, a
hook 50 may be formed in the polymeric shell 12 of an elastic
repositioning appliance 10 for use in mounting a flexible band 52.
Such a hook 50 may resemble traditional hooks found in dental care,
or it may be specially designed for use with elastic repositioning
appliances. The embodiment illustrated in FIG. 9 may be produced by
a series of production steps. First, a mold of the dentition is
produced by any method. Second, FIG. 10A, a wedge or similar
protruding mass 54 is then mounted on the mold 55 in the location
desired for the resulting hook. It may be appreciated that such a
protruding mass 54 may be formed in the original mold 55 by a
variety of methods, particularly in the case of computer-guided
production methods. Next, a polymeric sheet is thermoformed over
the mold 55 to form the appliance 10. The appliance 10 may then be
trimmed along the dashed line 56, FIG. 10B, and the polymeric
material removed from the joining area 57 to create a hook 50 shown
in FIG. 9.
In another embodiment, shown in FIG. 11, a spring 60 may be formed
in the polymeric shell 12 of an elastic repositioning appliance 10
for use in transmitting repositioning force to one or more teeth.
Such a spring 60 may resemble traditional springs found in dental
care, or it may be specially designed for use with elastic
repositioning appliances. In this example, the spring 60 is
comprised of a pre-formed strip or portion of the polymeric shell
12 which engages an attachment body 62 mounted on an underlying
tooth 64. The attachment body 62 is accessible through a window 66
in the appliance 10.
In further embodiments, larger protrusions may also be formed in
the polymeric shell to provide additional support for the appliance
and/or to provide orthodontic functions. Such a protrusion may form
a palatal bar 70, as shown in FIG. 12. Here, a palatal bar 70 is
formed in the polymeric shell 12 itself. In addition, a variety of
palatal bars may be formed in the shell, such as a low hanging
transpalatal bar for control of vertical dimension. These may
provide orthodontic functions as described above in relation to
conventional palatal bars, and they may also provide support for
the appliance 10. This may be particularly useful in highly
flexible appliances. For increased support of the construction, the
protrusion may be a corrugated palatal bar 71, as shown in FIG.
13.
In still further embodiments, protrusions in an elastic
repositioning appliance may assist in holding the elastic appliance
in place when it is properly inserted and positioned. Such
protrusions may be divots 74 sized and located to contact
interdental areas 76 of the patient's teeth 78, often near the
gingival margin 79 as shown in FIG. 14A. Such placement may provide
additional friction and "grab" in dental regions conducive to this
effect. Such divots 74 may be most visible by viewing the hollow
cavities of the appliance 10, as shown in FIG. 14B. These
protrusions may be solid divots 80 adhered to or embedded in the
polymeric shell 12 to inwardly protrude from the wall.
Alternatively, the protrusions may be formed divots 82 in the wall
of the polymeric shell 12 so that essentially the wall protrudes
inwardly in these areas. As shown, the divots may be of any shape,
number and configuration, including paired divots 84 and single
divots 86 as shown.
Similarly, these protrusions may be a continuous protrusion
contacting more than one tooth along the gingival margin and the
interdental areas. This is illustrated in FIG. 15A as a continuous
protrusion 90 is shown along the edges of the hollow cavities of
the appliance. This may be a solid protrusion 92 adhered to or
embedded in the polymeric shell 12 to inwardly protrude from the
wall, or it may be a formed protrusion 94 in the wall of the
polymeric shell 12 so that essentially the wall protrudes inwardly
in these areas. When the appliance is positioned over the teeth,
such a protrusion 90 may fit in the undercut of the tooth 64 along
the gingival margin 79, as shown in FIG. 15B. Here a solid
protrusion 92 and a formed protrusion 94 are shown in
cross-section. Such positioning along the undercut of the teeth may
assist in holding the appliance in place. It may be appreciated
that such a protrusions may be sized, formed and located in any
combination within the polymer shell so as to assist in holding the
appliance in a desired position.
In another embodiment, the one or more protrusions may form a bite
plate. A bite plate is a device which prevents the teeth from
closing completely. The resulting open state, or disclusion, may be
useful for a number of orthodontic treatments, including crossbite
correction and controlled passive eruption. To provide anterior
disclusion, an elastic positioning appliance 10 may have an
increase in thickness of material 100 in the posterior occlusion
regions of the polymeric shell 12, as shown in FIG. 16. The
increase in thickness of material 100 may be applied to the
appliance 10 or formed by the appliance 10 to create a protrusion
over the designated occluding surfaces. Similarly, as shown in FIG.
17, posterior disclusions may be provided by forming a protrusion
102 in the polymer shell 12 which extends at least a portion of an
upper palatal region with added thickness. This protrusion may be
formed in the appliance 10 or applied to the surface of the
appliance 10.
Alternatively, posterior disclusions may be provided by forming a
protrusion in an upper lingual or lower facial anterior region, as
depicted in FIGS. 18A and 18B. Here, the bite is shown in
cross-section, with an upper incisor 110 overlapping a lower
incisor 112 and a molar 114 positioned for reference. In FIG. 18A,
the polymeric shell 12 of an elastic positioning appliance 10 is
shown covering the upper incisor 110. On the lingual surface of the
shell 12, a protrusion 116 is shown which may contact the lower
incisor 112 during biting, thus acting like a bite plate. This
protrusion 116 may be formed into the polymeric shell 12 or applied
along the lingual surfaces of the appliance 10. Such an arrangement
may thus provide posterior disclusions. Similarly, the polymeric
shell 12 may cover the lower incisor 112, as shown in FIG. 18B. In
this case, a protrusion 118 on the facial surface of the shell 12
is shown which may contact the upper incisor 110 during biting.
Again, this protrusion 118 may be formed into the polymeric shell
12 or applied along the facial surfaces of the appliance 10. This
arrangement may also provide posterior disclusions.
Referring to FIG. 19, many patient's dentition present a gap 120 or
space between adjacent teeth 67. Such a gap 120 may be the size of
a tooth 67, as may be the case when a tooth is extracted, or the
gap 120 may be larger or smaller than the size of a typical tooth
67, as is often the case due to general misalignment of the teeth.
In either case, an elastic positioning appliance 10 may be made to
be positioned over the gap 120 and the surrounding teeth 67 with a
space filler aligning with the gap 120. In a preferred embodiment,
shown in FIG. 20, the space filler may be a cavity 122 in the
polymer shell 12 having the shape of a tooth. Thus, the space
filler may act as a "pontic", a fake tooth placed where a tooth is
missing to give the appearance of the presence of a tooth.
Likewise, such a cavity 122 may have the shape of any portion of a
tooth, dental feature, sphere, oval or three-dimensional curved
and/or flat sided object for any desired effect. To further conceal
the presence of a space or gap 120 between teeth 67 during
orthodontic treatment, the space filler may be opacified, as
depicted by shading 124 in FIG. 20.
In addition to improving cosmetic appearance, a space filler may
also provide structural support for the elastic appliance. When a
space filler is a cavity, as described above, the presence of the
cavity improves the structural integrity of the appliance by
providing a uniform geometry. Alternatively, a space filler may be
any number of structures providing similar support. In a preferred
embodiment, shown in FIG. 21, the space filler may be a structure
130 formed between two cavities in the polymeric shell 12 of an
appliance 10. The structure 130 may be comprised of the facial wall
132 and lingual wall 133 of the polymeric shell 12 fusing together
to form an at least partially solid slab or bridge. In addition,
suitable fillers or reinforcements may be used in the fusing or
similar process for added support. Likewise, a corrugated structure
135 may be formed between the cavities, as shown in FIG. 22. Such
corrugation may further reinforce the structure for added support.
In any case, a designated cavity 122 or structure 130, 135 in the
polymeric shell 12 may be designed to align with a gap 120 between
adjacent teeth 67 when the appliance 10 positioned over the
patient's teeth for improved cosmetic appearance and/or structural
support.
Although forming protrusions or adding additional material to
elastic repositioning appliances may provide useful features in
orthodontic treatment, it may also be beneficial to remove material
or form windows in an appliance. Referring to FIG. 23A, if the
occlusional surfaces 140 of an upper appliance 142 and a lower
appliance 143 are relatively thick, simultaneous wearing of the
appliances 142, 143 may provide unwanted disclusion of the teeth.
For example, when closing the jaws, the double layer of occlusional
surfaces 140 between the jaws may cause the posterior teeth to
prematurely contact, thus preventing the anterior teeth to suitably
close. This may be avoided by reducing or eliminating the
occlusional surfaces of the appliances, as shown in FIGS. 23B and
23C. In a preferred embodiment, shown in FIG. 23C, a polymeric
shell 12 of an appliance 10 may have a plurality of windows 150 in
the portions which cover the occlusal surfaces of the teeth. In
this example, segments of the shell 12 are still present along the
facial surfaces 152 and lingual surfaces 153 of the appliance 10
and across the interdental regions 154 or spaces between the teeth.
When such an appliance is placed over the upper teeth 155 and lower
teeth 156, the teeth may interdigitate, as shown in FIG. 23B.
Interdigitation of at least portions of the upper and lower teeth
may benefit tooth and jaw orientations, leading to improved
treatment, appearance, comfort and consequently patient
compliance.
Removal of material may be aided by the use of a release tab 200,
as shown in FIGS. 24A and 24B. A release tab 200 may be used to
remove a layer of material from the polymeric shell 12 or to remove
an entire portion of the shell 12, such as to either create a
window, as described above, or to eliminate the shell 12 from
covering specific teeth or portions of the patient's teeth.
Referring to FIG. 24A, a release tab 200 may be embedded in the
polymeric shell 12 along a line 202 for future separation between
portion A (shaded) and portion B. Although such a line 202 is
depicted as a dashed line adjacent to the tab 200 edge, such a line
202 may lie directly over the tab or in any close relation to the
tab 202. In the case of a polymeric shell 12 comprised of multiple
layers of material, the tab 200 may be embedded between the layers
with a portion exposed for grasping. By grasping the tab 200 and
pulling the tab 200 along its length, one or more layers of
material may be released along a line 202 of separation and removed
from the shell 12. In this example, the result may be portion A
comprising two layers of material and portion B comprising only
one. Alternatively, the result may be portion A comprising one or
more layers and portion B removed entirely. Other combinations or
examples are possible. Such alterations may be beneficial for
patient comfort, ease of use, or obtainment of orthodontic
repositioning goals, to name a few. FIG. 24B illustrates a
preferred embodiment of placement of such a release tab 200 in a
polymeric shell 12 of an elastic repositioning appliance 10. The
tab 200 may be placed to encircle areas 206 of the occlusional
surfaces of the appliance 10. Thus, the orthodontic treatment of a
patient may allow material in these areas 206 of an appliance 10
for a given duration of the treatment plan. At a given point in the
treatment, the orthodontic practitioner may prefer to remove a
layer of material or the material entirely in these areas 206
during a patient office visit. The practitioner may perform such a
removal by pulling on the appropriate release tabs 200 as described
above. This may thus reduce time and cost of patient treatment.
Although the forgoing invention has been described in some detail
by way of illustration and example, for purposes of clarity of
understanding, it will be obvious that various alternatives,
modifications and equivalents may be used and the above description
should not be taken as limiting in scope of the invention which is
defined by the appended claims.
* * * * *
References